Mean field ring polymer molecular dynamics for electronically nonadiabatic reaction rates

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Quantum Dynamics

Background:

• Electron transfer (ET) is fundamental to many chemical and biological processes.
• Accurately calculating ET rates in condensed phases, especially for multi-state systems, remains a challenge.
• Existing methods often struggle with complex dynamics and non-adiabatic effects.

Purpose of the Study:

• To develop a novel computational method for calculating electron transfer rates.
• To accurately model multi-state, multi-electron condensed-phase ET processes.
• To capture rate behaviors in both the normal and inverted Marcus regimes.

Main Methods:

• Mean field ring polymer molecular dynamics (RPMD) combined with path integral formulation.
• Transition State Theory (TST) with an exact path integral in discrete electronic states and continuous nuclear coordinates.
• Dynamic recrossing corrections obtained from real-time dynamics simulations.

Main Results:

• The method achieves remarkable agreement with Fermi's golden rule rates for non-adiabatic ET in the normal Marcus regime.
• Accurate dividing surfaces in TST calculations are crucial for reliable rate predictions.
• A reaction coordinate based on electronic state populations successfully captures rate turnover in the Marcus inverted regime.

Conclusions:

• The developed mean field RPMD method provides an accurate and versatile tool for ET rate calculations.
• The approach is capable of handling complex condensed-phase ET phenomena, including non-adiabatic effects.
• This work advances the computational modeling of electron transfer processes in chemistry and beyond.